In this paper we propose a simple method to extract edges from Polynomial Texture Maps (PTM) or other kinds of Reflection Transformation Image (RTI) files. It is based on the idea of following 2D lines where the variation of corresponding 3D normals computed from the PTM coefficients is maximal. Normals are estimated using a photometric stereo approach, derivatives along image axes directions are computed in a multiscale framework providing normal discontinuity and orientation maps and lines are finally extracted using non-maxima suppression and hysteresis thresholds as in Canny’s algorithm. In this way it is possible to discover automatically potential structure of interest (inscriptions, small reliefs) on Cultural Heritage artifacts of interest without the necessity of interactively recreating images using different light directions. Experimental results obtained on test data and new PTMs acquired in an archaeological site in the Holy Land with a simple low-end camera, show that the method provides potentially useful results.

Edge Detection on Polynomial Texture Maps

GIACHETTI, Andrea
2013-01-01

Abstract

In this paper we propose a simple method to extract edges from Polynomial Texture Maps (PTM) or other kinds of Reflection Transformation Image (RTI) files. It is based on the idea of following 2D lines where the variation of corresponding 3D normals computed from the PTM coefficients is maximal. Normals are estimated using a photometric stereo approach, derivatives along image axes directions are computed in a multiscale framework providing normal discontinuity and orientation maps and lines are finally extracted using non-maxima suppression and hysteresis thresholds as in Canny’s algorithm. In this way it is possible to discover automatically potential structure of interest (inscriptions, small reliefs) on Cultural Heritage artifacts of interest without the necessity of interactively recreating images using different light directions. Experimental results obtained on test data and new PTMs acquired in an archaeological site in the Holy Land with a simple low-end camera, show that the method provides potentially useful results.
2013
9783642411809
Polynomial Texture Maps; Edges; Cultural Heritage
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11562/612751
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 10
  • ???jsp.display-item.citation.isi??? 6
social impact